Ductrung Huynh Tong, 18, dressed in red and pink jail clothing, was arraigned in San Jose by Santa Clara County Superior Court Judge Hector Ramon, who ordered him held without bail and set his plea hearing for Feb. 3.

Tong and his twin brother Anh Tong were arrested by San Jose police for the killing of Richard Phan, who was stabbed around 1:30 a.m. Sunday in the 3400 block of Suncrest Avenue at a party meant to celebrate the birthday of Phan’s female friend.

Deputy District Attorney Dan Fehderau said Wednesday that Anh Tong was still in custody and that the investigation into the case was ongoing.

Fehderau said the statement of facts in the case was sealed and declined to comment further.

A Superior Court clerk said no charges have been filed yet against Anh Tong.

Phan, of San Jose, who had been invited by his friend to the party, died at a hospital about 30 minutes after the stabbing, police said.

The Tong brothers had been invited to the party by another guest, San Jose police spokesman Officer Albert Morales said.

Phan may have been attempting to break up a fight outside the home just before he was stabbed, Morales said.

Officers took the Tongs into custody after witnesses said they were not sure which of the twin brothers stabbed Phan because they looked so much alike, Morales said.

After the brief court hearing Wednesday, about 15 people who came to see Tong left the courtroom and congregated outside but declined to comment on the case.

Phan was a senior at San Jose State University who was majoring in biological science, university spokeswoman Pat Lopes Harris said.